This disclosure generally relates to a manufacturing method, and more particularly to a rapid manufacturing process for building tooling that can be used to manufacture casting articles for casting processes.
Gas turbine engines are widely used in aircraft propulsion, electric power generation, ship propulsion and pumps. Many gas turbine engine parts are manufactured in a casting process. Investment casting is one known casting process. Investment cast parts can include relatively complex geometries, such as gas turbine engine airfoils requiring internal cooling passages. Blades and vanes are examples of such parts.
Investment casting utilizes a plurality of casting articles, such as shells and cores, that function as a casting system for manufacturing a part. In general, the casting system is prepared having one or more cavities that define a shape generally corresponding to the part to be cast. In some cases, a wax pattern of the part is formed by molding wax over a core. In a shelling process, a shell is formed around one or more of the wax patterns. The wax is melted and removed. The shell is hardened in a firing process such that the casting system is formed, and in some cases the shell includes one or more part defining compartments that include the core.
Specialized tooling is used to manufacture the casting articles employed in the investment casting process. Such tooling is manufactured out of aluminum or steel using milling, high speed machining, electrical discharge machining (EDM), or similar technique(s). Typical lead times for manufacturing the tooling can range anywhere from 8 to 28 weeks or longer.